Clamp



A. K. WATCH ER CLAMP Nov. 17, 1936.

Filed April 27, 1935 Patented Nov. 17, 1936 uns TA ES ATE? OFFICE CLAMP Application April 27, 1935, Serial No. 18,607

5 Claims. (Cl. 14A-303) This invention relates to `improvements in clamps. The improvements are highly adaptable for, although not to be coni-ined to, joiners clamps. Clamps of this character are used, for example, to hold or clamp parts together during the hardening of glue. In a conventional clamp structure to which these improvements may apply will be found a bar slidably supporting a clamp jaw propelled by some pressure applying means and an adjustable work rest or stop adapted for setting along the bar depending on the width of the pieces of work.

It is an object of this invention to provide an improved clamp structure wherein the adjustable work rest or stop is more vreadily released and reset on the clamp bar, is more delicately adjustable without sacrice of strength, and more firmly and positively grips the bar. As to the attachment the present device develops increased holding force as the work thrust, imposed by the clamping jaw, increases. Moreover these advantages are achieved in a structure of extreme simplicity, easily assembled and economically manufactured.

Other objects and certain advantages will be found in the description of the drawing, in which:

Figure 1 is a side view of a joiners clamp, incorporating the present improvement.

Figure 2 is a plan View of the joiners clamp.

Figure 3 is a sectional view taken on line 3 3, Fig. 2, detailing the holding means of the work rest.

Figure 4 is a sectional View taken on line 4 4, Fig. 3, with a portion of the work rest broken away.

Figure 5 is a View taken similar to Figure 3, but depicting the holding means manually released for movement of the work rest forwardly on the clamp bar.

Figure 6 is a detail View showing one of the lock plates of the holding means in perspective.

Referring to the drawing, a clamp support bar I has a stationary nut I I xed on one end thereof. A clamping jaw I2 is slidably mounted on the bar. Propulsion of this jaw is produced by a screw I3 rotatably socketed in the jaw and traversing the nut. For the purpose of the socketed connection the end of the screw is annularly grooved at I. A screw I in the clamping jaw projects into the groove I4 with the end of the screw inserted into the socket of the clamping jaw. Rotation of the screw is manually accomplished by means of a crank I8 on the extended end of the screw. The work rest II incorporating the present improvements is adjustably slidably mounted on the bar.

The bar I is an I-beam in this instance incorporating a transversely curved top surface. The work rest or stop element II includes a passage or opening I8 permitting sliding engagement of the element over the clamp bar (see Figure 3) The work rest is cored out to provide a chamber IS for the holding means.

A plurality of lock plates 20 are mounted in the chamber I9. These plates are stacked and are disposed in position slightly cocked from transverse plane relative to the top surface of the bar. They are conned to this cocked position by virtue of the fact that the distance between the top surface of the bar and the top wall 2I of the chamber is less than the length of the lock plates. The top wall thus provides the thrust receiving abutment for the upper ends of the plates.

A coil spring 22 is located on a stud 23 eX- tended from the inner side wall of the chamber land is under compression against the plates as a unit. The plates are thus normally wedged between the top surface of the bar and the top wall of the chamber. The lower edges of the plates are ground to provide sharp edges 2li. The angle .of grinding is such as to clear the lower edge surfaces of the plates, whereby only the sharp edges may engage the bar. These edges are curved to t the curved surface of the bar (see Figure 4) Since these sharp edges are at the rear sides of the plates and due to the cocked position of the plates, rearward movement of the work rest is precluded unless the plates are further cocked. However, movement toward the work is accomplished simply by manual translation of the work rest in that direction without displacing the plates (see Figure 3).

Now in order to release the work rest for movement away from the work, a manually operated lever 25 is provided. This lever is Ushaped (see Figure 2) and has its ends turned toward the clamp bar as at 26 and toward each other as at 21. 'Ihese ends Z'I traverse arcuate clearance slots 28 in the respective side walls of the work rest. This engagement of the ends 2'I through the slots mounts the lever in position against displacement relative to the work rest.

The downwardly turned portions 26 are engageable against external abutment flanges 29 of the work rest to provide the rocking point for the lever. A thumb hold flange 30 on the work rest is provided to permit more convenient operation 0f the lever (see Figure 5). As the lever is pulled ness of the downwardly bent portions 26 of the lever as compared to the rearward extent of the- Promptly upon release of the lever theVA lever. lock plates assume normal wedging position.

Having described my invention, I claim:

1. A clamp, comprising, a bar; a clamping-jaw slidably mounted on said bar, means for adjusting said clamping jaw, a workrrest slidably adjustably mounted on said bar, said WorkV rest cored to provide a chamber, a plurality of lock plates mounted in stacked relationv in said work rest chamber, spring means for urging said plates kas a unit into cocked wedged position between a wall of said chamber and said bar, said plates having sharp-edges engageable with the bar, and a lever engaging the plates on the-side opposite to the spring means for unitarily moving said plates, and thereby releasing the same from holding position and permitting adjustment of the work rest on the bar.

2. A clamp, comprising, a bar, a clamping jaw slidably mounted on said bar, means for adjusting said clamping jaw, a work rest slidably adjustably mounted on said bar, said work rest cored to provide a chamber, a lock plate in said Work rest chamber, spring means for urging said plate into wedged position between a wall of said chamber and said bar for rigidly engaging an edge of the plate with the surface of the bar, and a lever engaging the side of the plate opposite to the side engaged by the spring means for moving said plate from wedged position for Ydisengaging said edge from the bar.

3. A clamp, comprising, a bar, a clamping jaw slidably mounted on said bar, means for adjusting said. clamping jaw, a work rest slidably adjustably. mounted on said bar, a plurality of lock plates mounted in stacked relation on said work rest, said rest including a thrust receiving abutment, means for urging said plates as a unit into cocked wedge position between the thrust receiving abutment and said bar, said plates having sharp edges engaging the bar, and a lever loosely contacting that plate on the side of the stacked plates opposite to the means for urging the plates, said lever adapted to move said plates into further cocked position for disengaging the plates from the bar and releasing the work rest.

4. In a clamp of the type including a bar and a clamping jaw adjustably mounted thereon, a work rest slidably mounted on the bar, a plurality of lock plates in stacked relation mounted in the work rest between a thrust receiving abutment wall thereof and the bar, said wall and bar spaced aparta distance less than the length of the plates, spring means for wedging said plates as a unit into cocked position between said wall and said bar, said plates including sharp cross edges engaging the bar and providing a rm grip therewith, which grip increases asv pressure is put on the'work rest tending to further wedge the plates, and leverage means in loose contact with the plate ofthe set ofy plates which is opposite to the spring means for further cocking said plates to release the work rest for movement along the bar.

5.v A clamp, comprising, a bar, a clamping jaw slidably mounted on said bar, means for adjusting said clamping jaw, a work rest slidably adjustably mounted.V on said bar, 'said work rest cored to provide a chamber, a plurality of lock plates mounted in stacked relation in saidlwork rest chamber, spring means for urging said plates as a unit into cocked wedge position between a wall of said chamber and said bar, said plates having sharp edges engageable with the bar, a Ux-shaped lever having arms extending downwardly and then inwardly at their ends, said work rest providing clearance slots, said inwardly turned ends projecting through said slots and engaging the plurality of plates as a unit at the forward side thereof, abutment flanges on the work rest engaged by the bends of the lever forming the downwardly turned portions, and a stud in the work rest limiting release movement of the lock plates as caused by lifting of the outer end of said lever.

ALBERT KEITH WATCHER. 

